Improvement in lime-kilns



J. MCADAMS.

Improvement in Lime-Kilns. No. 131,2Q6; Patented Sep.10, 1872.

A'IEN JOHN MGADAMS, OF MOUNT PLEASANT, PENN SYLVANIA, ASSIGNOR TO HIMSELF AND O. D. PAGE, OF GREECE, NEW YORK.

IMPROVEMENT IN LIME -KlLNS.

Specification forming part of Letters Patent No. 131,290, dated September 10, 1872.

Specification describing a certain Improvement in Lime-Kilns, invented by JOHN M0- ADAMs, of Mt. Pleasant, in the county of Westmoreland and State of Pennsylvania.

Nature of the Invention.

My improvement belongs to that class of lime and cement-kilns in which the stone and coal are mixed in alternate layers and the combustion is carried on in the shaft of the kiln. The invention consists in the employment of coping-blocks, arches, and walls of a peculiar kind, and an iron cap surmounting the same, whereby the lime is discharged more freely at the bottom and air is supplied to the center to support combustion, as hereinafter blocks D D, which are of A or saddleform, with the apexes upward. These blocks are made of fire-brick, and crossjeach other at right angles, thus dividing the cross-area of the cupola into four divisions, a a a a, which constitute discharge-passages for the calcined material into the draw-pit below. The under sides of the walls underneath the coping-blocks are formed into arches b b, which also cross each,other at I right angles, as shown in Fig. 1, thus insuring a ready passage to the lime as it falls through. On top of the central or crossing portions of the coping-blocks is fitted an iron cap, E. This cap is made convex on top to deflect the lime, and is made hollow to furnish an air-chamber, 0. Its verticalflange has four A-shaped notches d d to stride the apexes of the coping-blocks, and four or more intermediate ports or airpassages ff to allow the escape of air from the air-chamber upward into the center of the cupola. The air-chamber receives its supply of air from the arch of the draw-pit by means of the passages h, which passes up .into the center beneath the arch of the coping-blocks. The cupola is charged in the usual way with alternate layers of stone and coal, and the fire is applied. The tendency is to burn most upon the outside or next to the walls of the cupola. This is caused by the stone falling toward the center as the discharge goes on at the bottom. Much difficulty has been experienced from this result heretofore, for the falling in toward the center not only prevents perfect combustion at that point, but it also disturbs the layers of stone and coal by throwing them out of line. It leaves the sides loose and open, so that the fire can penetrate through,

while the center is solid and impenetrable.

The result is that clinkers will form upon the outside, while the stone in the middle will pass through comparatively unburned.

By the use of the arched and coping blocks and convex cap the center portion of the lime in the cupola is held up and prevented from falling in. The discharge is at the sides instead of the center. This preserves the horizontal line of the layers of coal and stone. The cap E is also effective in helping to hold up the center, and by its convex top it deflects the lime outward so that it will not clog. Its most important function, however, is to furnish a constant supply of air to the center of the mass of stone, which, by rising upward, supplies the combustion in the middle. The currents of air pass out through the ports f j in a thin sheet all around the cap, and are diffused through the whole mass. This method of supplying air obviates a difficulty long experienced in this class of lime and cementkilns. It saves much fuel, produces a better quality of lime, and requires less attention from the operator.

The improvements I have above described are particularly applicable to coal burning lime-kilns, Where the stone and coal are used in alternate layers, and where the combustion is carried on in the cupola itself, and as such are new, so far as I am aware.

In place of the air-passage h opening from the arch of the draw-pit, air-passages may be made in any or all of the walls which support Enron.

the coping-blocks, and enter the air-receiver at the junction of the coping-blocks.

Claims.

What I claim and desire to secure by Letters Patent, is-

1. In a coal-burning lime or cement kiln the rightangled coping-blocks D D, con structed as a division between the cupola and draw-pit, when the same are formed so as to produce the division-passages co a for the discharge of the calcined product from the center outward as herein shown and described.

2. I claim, in a coal-burning lime or cement 

